Shrinking hammer for sheet metal working



June 10, 1952 D, D, scHMELNG 2,599,786

SHRINKING HAMMER FOR SHEET METAL WO/RKING Filed Nov. 3, 1950 INVENT'OR DARRELL D. SCHMELI NG ATTOR NEYS Patented June 10, 1952 Darrell D. Schmeling, Watertown, S. Dak.

Application November 3, 1950, Serial No 193,808

'7 Claims. (Ol. 81-15) This invention relates to shrinking .hammers for sheet metal working.

In sheet metal working, such as in the straightening of automobile bodies, etc. where the metal has previously been distorted and expanded to some extent. the metal is commonly returned to its original shape by a shrinking process. This process includes the intense heating of a very local area of the portions of the v. a

metal previously distorted and, While the metal is still hot, hammering it into its original shape with what is known as a shrinking hammer. By heating a small and very local area intensely, the respective molecules of the metal within the center of that area tend Ato disperse and move into a more compact relation with respect to each other around the periphery ofthe area and adjacent the molecules of the unheated portions. Then when the metal cools, the central portion of the heated area contracts and shinks rapidly, thereby tending to return the surface of the metal to its original smooth condition.

i The process described above has previously been. accomplished by' one man applying an acetylene torch or similar heating element to the local area of metal to be shrunk and by a second man following himfwith an anvil and a hammer with which the metal is hammered into shape. The anvil, of course, must be heldbehind the metal while the hammer is applied to its opposite side. My invention is directed toward the simplification of this operation in so far as efliciency is concerned.

It is a general object of my invention to provide a novel and highly improved shrinking hammer of cheap and simple construction and of eficient operation.

A more specific object is to provide a shrinking hammer of increased efficiency whereby one man may readily and easily perform a metal shrinking operation which previously required the labor of at least two men.

Another object of my invention is to provide a shrinking hammer which will permit one man to perform a complete metal shrinking operation which is continuous in nature in order to effect more efficient and economical sheet metal working.

These and other objects -and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views and in which:

Figure 1 is a side elevational view of one embodiment of my invention shown in position for proper use to shrink a piece of metal.

Figure 2 is a bottom elevational View same.

of the Figure 3 is a fragmentary Sectional view taken along line 3-'3 of Figure 2. a

One embodiment of my invention may include as shown in Figures 1-3, a shank '5 having fixedly vIS mounted on one of its end portions a rigid noncombustible block 6. A's shown the shank 5 is preferably made of wood while the block 6 is preferably constructed of metal. The block 6, as shown, has a generally cylindrically shaped portion 1 vextending downwardly therefrom and carrying a relatively broad and flat head |8 at its lower end. The head i8 has a smooth pounding surface 9 which faces downwardly and has a peripheral recess IU formed therein. Extendof metal. As shown this conduit I3 extends forwardly to a point adjacent the block 6 from which it extends downwardly and passes through the central portion of the cylindrically shaped portion 1 and terminates with a nozzle [4. 4This nozzle l4 is disposed within the confines of the recess in of the head 8 as best shown in Figure 2. It also terminates in substantially the same plane as the smooth pounding surface .ll of the head 48. As best shown in [Figure 2 its voriflce l5 is of a relatively small diameter. i

The rear end portion of the conduit l3 has connected thereto by means of a clamp I 6, a flexible conduit ll, the other end of which is connected to a source of highly-inflammable gas (not shown) such as acetylene. Through this conduit ll the acetylene gas may be forced through the conduit I3 and outwardly through the nozzle M to provide, when lighted, a fiame IB of high intensity. This fiame 18, as best shown in Figure 1, is directed downwardly to play upon the distorted sheet metal surface indicated in Figure 1 as 19.

In operation the metal worker will cause the flame b8 to play upon the distorted metal I9 for a brief period at the proper distance therefrom so as to obtain maximum heat from the flame. After the distorted portion l9 has been sufliciently heated to cause the metal to shrink the metal worker will tap that area gently with the smooth pounding surface wil of theA headj8 to cause the metal to resume its original shape. While the distorted portion I 9 is being hammered into its original shape as a result of the shrinking and' the gentle tapping, the area of sheet metal immediately adjacent thereto and ahead thereof will be heated by the :flame l8 preparatory to working the same. Thus it can be readily seen that the metal vworker will thereby be permitted to4 work forwardly continuously 'without interruption. With one hand he may man's labor by utilizing my invention.

In addition to the above, a metal worker may attain increased eficiency in his work since heH will have quicker access to the heated `area with this hammer than he would have'ifl another man' i were heating the area for him. By utilizing my hammer, the metal'worker maystrike the metal1 previously heated almost the instant' immediately after it has been heated. When two' men'arerequired for this operation, it is first necessaryfor i the man withV the .acetylene torch to move away from the heated areaito provideroom for the necessary movement ofthe Vman with theV hammerand anvil. g

inconvenience to the metal worker by transferring the. same directly through the shank 5.

.Thus it canbe seen that I have provided a shrinking hammer of cheap and simple construction which eliminates. the labor of one man and w hich will permit a single sheet metal worker to'readily and easily perform a metal s hrinking operation, inV a continuous manner.

v It will,.o f course, be understood that various changes Vmay ,be made in the form, details, arrangement and proportions of the parts without departing from the scope of my invention.

. What I claim is:

1 A s hrinking hammer for sheet metal workinghaving inA combination, a shank, a rigid, noncombustiblevblock fxedlyumounted on one end portion of vsaid shank,; at least a portion ofsaid block having a headjthereon, said head having a continuously flat outer surface, and a nozzle earriedby said shank,, said nozzle being adapted forficomrection to asource of highly combustible gas. andbeing arraneedto direct a burning. flame of such gasy adjacent'to butV not directly beneath said head whereby as .said head is applied to a section'v of sheet. metal .to work the same an area of'such metal immediately adjacent thereto will be heated-preparatory to being worked by said head.

,2. .A ShrinnrtgV hammer `for sheet metal working having in combination, a shank, a metal block i'lXedlyl mounted on one end` portion of said shank, at-leasta. portion of said block having a head thereon., rsaid head vhavinga continuously nat outer surface disposed in a plane substantially parallel'to. s aidishank, and a nozzle carried by said shan-k, .said nozzlebeing adapted for connectiontoa source olf highly. combustible gas and being' arranged to direct; a;` burning flame Of' 511011 gasadjacent tofibut not directly. beneath said headwherebyas saidheaid is applied to a section ofsheetmetal to work. thesame an area of metal immediately adjacentjthereto Will' be heated.

preparatory to being Workedby said' head.

-3.-A shrinkinghammer for sheet met'alworkinghaving in combination, a shank, a metal head fixedly secured to Vone end portion of said shank, said .headlhavinga continuously smooth exterior poundingisurfacaand a nozzle e arried'by said shank, and disposed adjacent said pounding surface, said nozzle being adapted for connection to a source of highly combustible gas and being .arranged to-direct a burning flame-of such gas adjacent to but not beneath said head whereby as said head is ,applied to a section of sheet metal to work the same an area of such metal immediately adjacent thereto will be heated in preparation for being worked by said head.

4. A shrinking hammer for sheet metal working having in combination, a shank, a metal head fixedly secured to one end portion of said shank,

` said' head'having .a'continuously smooth downfthjat' by positioning the wardly` facing pounding surface, and a nozzle mounted on said head adjacent its periphery, said nozzle having conduit means connected thereto for connection with a sourceof highlycombustible gas and being directed downwardly toward a point beside .said head whereby as saidhead is applied to a sectionV Vof sheet metalto work the same, -said nozzle may direct a burning ame to an. area. ofnsuch metal immediately adjacent to prepare the same tobe Worked by said head.

.5.,A-'shrinking hammer for. sheet metal working having in combination, 'a shank, a rigid,` noncombustible head fixedly secured to one end portion of said shank, said head having a continuously smooth downwardly facing pounding. surface, and a nozzlecarriedby said-shank and disposed adjacent the periphery of said head, said nozzle having conduit means connected thereto for connection with a source of highly infiammable gas Vand being directed downwardly toward a point beside said head whereby as said head is applied to, a section of sheet metal to work the same, said nozzle may direct a burning flame to an area of. such metal immediately adjacent theretoto prepare the same to be worked by said head.

6. A :shrinking hammerfor sheet metal working havingin combination, a shank, a rigid, noncombstible block fixedly rmounted on one end portion of said shank, said'block having .a neck portion and a head portion, said head portion having a continuously' smooth downwardly facing poundingsurface, a nozzle carried by said shank and disposed adjacent the periphery of said head portion and slightly above said pounding surface, said nozzle. being directed'downwardly toward a point immediately besidefsaid pounding surface wherebyl as said head is applied to a section of sheet' metal to work the same, said nozzle may direct a burning ame to an area'of such metal 'immediatelyadjacent such section to prepare the Country Date Number Great Britain July l'Tl 1924 

